Synthesis of new spiro compounds proceeding from 11H-Indeno[1,2-b]quinoxalin-2-one

Abstract

Reaction of 11H-indeno[1,2-b]quinoxalin-2-one with semi(thiosemi)carbazides in ethanol resulted in semi(thiosemi)carbazones which at boiling in acetic anhydride underwent cylization yielding N-{3′-acetyl-3′H-spiro[indeno[1,2-b]quinoxalin-11,2′-[1,3,4]oxa(thia)diazol]-5′-yl}acetamides. Aldol crotonic condensation of 11H-indeno[1,2-b]quinoxalin-2-one with methyl N-(4-acetylphenyl)carbamate afforded the corresponding chalcone that at boiling in anhydrous ethanol with hydrazine hydrate for 1 h formed a spiro compound with a pyrazole ring. Five-component condensation of ninhydrin, 1,2-phenylenediamine, sarcosine, malononitrile (or ethyl cyanoacetate), and 4-formylphenyl N-phenylcarbamate in a mixture EtOH — [bmim]Br led to the formation of 4-{3′,3′-dicyano(or 3′-ethoxycarbonyl-3′-cyano)-1′-methylspiro[indeno[1,2-b]quinoxaline-11,2′-pyrrolidin]-4′-yl}phenyl N-phenylcarbamates.